Question 1

Sterilizing ﬁlters have a pore size of 0.22 μm. Which of the following statements is true?

Accepted Answer

A)   Bacterial cells are typically between 1-10 μm and pass through the ﬁlter, whereas most viruses are between 20 and 200 nm and are therefore blocked.
B)   Bacterial cells are typically between 1-10 μm and are blocked by the ﬁlter, whereas most viruses are between 20 and 200 nm and therefore pass through.
C)   Bacterial cells are typically between 1,000-10,000 nm and pass through the ﬁlter, whereas most viruses are between 20 and 200 nm and are therefore blocked.
D)   Bacterial cells are typically between 1-10 nm and are blocked by the ﬁlter, whereas most viruses are between 20 and 200 μm and therefore pass through.

Question 2

Host cells of viruses include ______.

Accepted Answer

A)   humans and other animals
B)   plants and fungi
C)   bacteria
D)   protozoa and algae
E)   All of the choices are correct.

Question 3

Creutzfeldt-Jacob disease is _______.

Accepted Answer

A)   caused by a chronic latent virus
B)   initiated by an oncogenic virus
C)   caused by a viroid
D)   a spongiform encephalopathy of humans
E)   also called "mad cow disease"

Question 4

Which of the following is a true statement regarding lysogeny?

Accepted Answer

A)   Once the phage genome is integrated into the host cell, it remains there permanently.
B)   The host bacterial cell acquires new characteristics that are often detrimental to humans.
C)   It halts the viral life cycle because the phage genes are no longer replicated.
D)   The host bacterial cell is lysed once the phage genome is integrated.

Question 5

A negative RNA virus must ﬁrst ________.

Accepted Answer

A)   synthesize a DNA copy of its genome
B)   synthesize a negative RNA copy of its genome
C)   synthesize a positive RNA copy of its genome
D)   transcribe reverse transcriptase
E)   transcribe RNA polymerase

Question 6

Viruses that infect bacteria are speciﬁcally called ______.

Accepted Answer

A)   viroids
B)   prions
C)   bacteriophages
D)   satellite viruses

Question 7

Reverse transcriptase synthesizes ________.

Accepted Answer

A)   a positive RNA strand from a negative RNA strand
B)   a negative RNA strand from a positive RNA strand
C)   viral RNA from DNA
D)   viral DNA from RNA

Question 8

Animal viruses have the ability to attach to and enter almost any animal host cell.

Accepted Answer

A) True 
 B)False

Question 9

In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.

Accepted Answer

A)   nucleus; cytoplasm
B)   cytoplasm; cell membrane
C)   cell membrane; cytoplasm
D)   cytoplasm; nucleus
E)   nucleus; endoplasmic reticulum

Question 10

A naked virus only has a/an ______.

Accepted Answer

A)   capsomere
B)   nucleocapsid
C)   envelope
D)   antigenic surface

Question 11

The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ______.

Accepted Answer

A)   adsorption to the host cells
B)   injection of only the viral nucleic acid into the host cell
C)   host cell synthesis of viral enzymes and capsid proteins
D)   assembly of nucleocapsids
E)   replication of viral nucleic acid

Question 12

When a bacterium acquires a trait from its temperate phage, it is called ______.

Accepted Answer

A)   transformation
B)   lysogenic conversion
C)   viral persistence
D)   transcription
E)   translation

Question 13

Who developed a rabies vaccine after realizing the disease was caused by something smaller than a bacterium?

Accepted Answer

A)   Leeuwenhoek
B)   Koch
C)   Pasteur
D)   Cohn
E)   Ivanovski

Question 14

Which of the following is not a typical capsid shape?

Accepted Answer

A)   Tetrahedral
B)   Complex
C)   Helical
D)   Icosahedron

Question 15

The core of every virus particle always contains ______.

Accepted Answer

A)   DNA
B)   capsomeres
C)   enzymes
D)   DNA and RNA
E)   either DNA or RNA

Question 16

Each virus is classiﬁed into a genus based on its host, target tissue, and type of disease it causes.

Accepted Answer

A) True 
 B)False

Question 17

How are viroids transmitted?

Accepted Answer

A)   Respiratory secretions
B)   Sex
C)   Plant seeds
D)   Blood products

Question 18

Bacteriophages do not undergo adsorption to speciﬁc host cell receptors prior to penetration.

Accepted Answer

A) True 
 B)False

Question 19

Mammalian viruses capable of starting tumors are ______.

Accepted Answer

A)   chronic latent viruses
B)   oncoviruses
C)   syncytia
D)   inclusion bodies

Question 20

The correct sequence of events in viral multiplication is ________.

Accepted Answer

A)   penetration, uncoating, synthesis, adsorption, assembly, and release
B)   uncoating, penetration, synthesis, assembly, absorption, and release
C)   adsorption, penetration, uncoating, synthesis, assembly, and release
D)   assembly, synthesis, uncoating, release, penetration, and adsorption
E)   adsorption, release, synthesis, uncoating, assembly, and penetration

Exam 6: Viruses and Prions

A negative RNA virus must ﬁrst ________.

Correct AnswerverifiedShow Answer

Which of the following is a true statement regarding lysogeny?

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Mammalian viruses capable of starting tumors are ______.

Correct AnswerverifiedShow Answer

Host cells of viruses include ______.

Correct AnswerverifiedShow Answer

A naked virus only has a/an ______.

Correct AnswerverifiedShow Answer

Reverse transcriptase synthesizes ________.

Correct AnswerverifiedShow Answer

Animal viruses have the ability to attach to and enter almost any animal host cell.

Correct AnswerverifiedShow Answer

Viruses that infect bacteria are speciﬁcally called ______.

Correct AnswerverifiedShow Answer

How are viroids transmitted?

Correct AnswerverifiedShow Answer

Creutzfeldt-Jacob disease is _______.

Correct AnswerverifiedShow Answer

Each virus is classiﬁed into a genus based on its host, target tissue, and type of disease it causes.

Correct AnswerverifiedShow Answer

Who developed a rabies vaccine after realizing the disease was caused by something smaller than a bacterium?

Correct AnswerverifiedShow Answer

The correct sequence of events in viral multiplication is ________.

Correct AnswerverifiedShow Answer

In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.

Correct AnswerverifiedShow Answer

The core of every virus particle always contains ______.

Correct AnswerverifiedShow Answer

The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ______.

Correct AnswerverifiedShow Answer

When a bacterium acquires a trait from its temperate phage, it is called ______.

Correct AnswerverifiedShow Answer

Which of the following is not a typical capsid shape?

Correct AnswerverifiedShow Answer

Sterilizing ﬁlters have a pore size of 0.22 μm. Which of the following statements is true?

Correct AnswerverifiedShow Answer

Bacteriophages do not undergo adsorption to speciﬁc host cell receptors prior to penetration.

Correct AnswerverifiedShow Answer

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In general, most DNA viruses multiply in the host cell's _, while most RNA viruses multiply in the host cell's _.

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